The advent of non-combustion smoking articles has brought about construction considerations that were not faced in the manufacture of conventional smoking articles. Such non-combustion smoking articles have the basic appearance of conventional cigarettes. However, beyond that outward appearance, they are very different.
Non-combustion smoking articles may include a short combustible fuel element and a flavor bed. The fuel element is mounted in one end of a reflective inner sleeve and extends from the sleeve. The flavor bed is contained within the inner sleeve and held in place by structures disposed across the inside diameter of the inner sleeve.
The inner sleeve, which has the fuel element extending from one end and the flavor bed contained within it, is enclosed by an air permeable, laminate outer sleeve which has aluminum foil layer at the inside diameter and a porous paper at the outside diameter. An end cap is fixed at the lighting end of the outer sleeve.
The outer sleeve may be formed from a fully laminated structure consisting of porous paper as the outside layer and a metal foil as the inside layer. The outer sleeve also may consist of a porous paper tube with metal foil disposed at its inner surface. In this latter case, the metal foil is connected to the porous paper only along an adhesive line that is disposed adjacent to one of the edges of the porous paper.
When the outer sleeve is made from either of the laminate, the metal foil at the inside diameter is used to reflect the heat radiated from a burning fuel element back toward the interior of the smoking article. The metal foil at the inside serves not only to reflect the heat, but to thermally isolates the fuel element from the outer porous paper layer. Thus, it acts as a heat shield.
The outer sleeve, with the combination within it that includes the fuel element, flavor bed, and inner sleeve, has a thin-walled tube fitted to its non-lighting end. This tube, which functions as an expansion chamber, serves as the mouth end of the smoking article. The distal end of this tube may be fitted with a filter. The outer sleeve with its contents and the expansion chamber may be overwrapped with cigarette paper.
There have been problems in the perforating the metal foil that serves as the heat shield in either configuration of the outer sleeve. The heat shield, besides thermally isolating the fuel element and reflecting the heat that is radiated by the burning fuel element, must also allow a predetermined amount of air to pass through it to sustain a burning fuel element.
The porous paper/metal foil laminate that is used for outer sleeves must have certain characteristics. Some are that the outer sleeves must have the porosity in CORESTA to allow a predetermined amount of air to pass through them and they must be reasonably sturdy to support the inner sleeve that disposed within it. Further, the outer sleeves have to have the outward appearance of a conventional cigarette and not contribute to the taste of the non-combustion smoking article when smoked.
The problem that arises with regard to perforating the metal foil laminate is that it must be perforated in such a manner that the amount of relieved metal foil is minimized. This is necessary for two reasons. First, the metal foil particles may clog the perforation apparatus. Second, it helps insure that there is an effective heat shield. That is, if the perforation holes are too large, large amounts of heat will be lost rather than reflected back to the interior of the smoking article. This may result in lower aerosol generation.
Besides the problems that were indicated immediately above regarding perforating the laminate structure, there also have been problems in forming the paper/paper, paper/metal foil, and metal foil/metal foil laminates which do not use adhesive in forming the laminates. It is preferable not to use glue or other adhesive in forming the laminates since they add significantly to the thickness of the resultant tube structure which is not helpful in forming the desired lightweight, thin-walled tubes.
A yet further problem has been forming lightweight thin-walled tubes in general from laminates.
In the manufacture of conventional smoking articles, there have been various methods for making filter tow, making and wrapping filter tow, wrapping tobacco, and wrapping tobacco and filter tow together that have involved the use of apparatuses that have an endless garniture belt. Such garniture belts go into, and through, a garniture to form the finished product.
In filter tow forming, the filter material is placed on the endless garniture belt and the belt carrying this material enters the garniture. In the garniture, the filter material is formed into filter tow by the garniture belt being folded over by folders that force the filter material into the desired shape. The filter material after being forced into this shape is passed through a heating section to complete formation of the filter tow.
In making and wrapping filter tow, and wrapping tobacco, a continuous strip of cigarette wrap is transported to the garniture on an endless garniture belt. As it is transported, an adhesive is placed along an edge of the cigarette wrap. The filter material or tobacco is then deposited in any conventional manner on the cigarette wrap. The garniture belt with the cigarette wrap, and tobacco or filter material disposed on it enters the garniture where the edges of the cigarette wrap are folded around the filter material or tobacco. In folding over the edges, a lap seal is formed by the edges of the cigarette wrap. The adhesive is the sealing agent at the lap seal. The seal is then cooled by a cooling bar and a continuous formed rod is output from the apparatus. In the case of wrapped filter tow forming, the formed filter tow is passed through a heating section before being moved adjacent the cooling bar.
Similarly, in wrapping tobacco and filter tow together, a continuous strip of cigarette wrap is transported toward the garniture on an endless garniture belt. First, an adhesive is applied to an edge of the cigarette wrap. Next, the tobacco and filter tow sections are alternatively, and adjacently, deposited on the belt. The combination enters the garniture where the cigarette wrap folds around both the tobacco and filter tow sections. Again, the edges of the cigarette wrap are overlapped to form a lap seal. The lap seal is cooled with a cooling bar and the continuous rod is output from the apparatus.
In constructing lightweight thin-walled tubes that are to be used as outer sleeves or expansion chamber tubes, there can be no beneficial use of tobacco or filter tow material which will act as a means around which the tubes may be formed.
In the past, the have been a variety of tube forming machines for making a number of different types of tubes. Because of the variety of uses of these tubes, there have been specific construction considerations with regard to the respective types of tubes, considerations which are not necessarily those for making lightweight, thin-walled tubes for use in the manufacture of non-combustion smoking articles. Hence, such machines do not solve the problem now faced in making lightweight thin-walled tubes for non-combustion smoking articles.
A final problem that has been encountered in the constructing lightweight thin-walled tubes is the accumulation of dust and particles in the process tube forming that if not removed from the lamination being used to form the tubes may result in the formation of defective tubes. The fact that such defective tubes have been formed, however, would not be discovered until much later in the manufacturing process. There has been no effective way to minimize the accumulation of the dust and particles to prevent this from happening.
The present invention overcomes these problems and provides an apparatus for laminating two or more paper and metal foil strips, paper strips, or metal foil strips, and forming them into a plurality of tubes that may be suitable used in the manufacture of non-combustion smoking articles.